1. Field of the Invention
The present invention relates to a facsimile machine for recording transmitted or copied images on cut sheets. More particularly, the present invention relates to a facsimile machine of a type which temporarily stores, in a memory, image data representative of the images desired to be recorded, before performing a recording operation with the image data onto cut sheets.
2. Description of the Related Art
Conventionally, a typical facsimile machine is capable of encoding and transmitting image data of a document read by a reading unit in a transmission mode. In reception mode, incoming image data is temporarily stored in an image data memory before being decoded and developed into record data in the form of dot data. The record data is then temporarily stored in a record data memory before being sequentially recorded in line increments on a record sheet such as a cut sheet or a roll paper.
In a facsimile machine of a type that can record on cut sheets, such as A4 or letter size sheets as the record sheet, recording processes are possible at several different recording speeds. An operator can select one of the several different recording speeds. Image data is transmitted from a remote facsimile machine at a transmission speed corresponding to the selected recording speed. Image data representative of several pages of document are sequentially transmitted from a remote facsimile machine and are first stored in an image data memory. Image data are sequentially retrieved at one-line increments from the image data memory to be decoded into line image data. The thus-prepared line image data are further developed into line record data in the form of dot data before being stored in a record data memory. A cut sheet is supplied to the recording unit of the facsimile machine and transported therethrough at a predetermined pitch for every line increment of record data retrieved from the record data memory and recorded on the sheet. When the entire sheet is recorded on, recording processes of the facsimile machine are interrupted, the sheet in the recording unit is discharged onto a discharged sheet tray of the facsimile machine, and a new cut sheet is supplied to the recording unit.
However, there has been known a problem with the above-described facsimile machine in that each time recording of a cut sheet is completed, the recording processes are interrupted while discharge of the completed sheet and supply of a new sheet are executed consecutively. During the period that the recording processes are interrupted, the image data for respective line images are sequentially retrieved from the image data memory, decoded and developed into the line record data, and then stored into the record data memory. The amount of the record data thus stored in the record data memory increases until remaining capacity in the memory unoccupied by the record data becomes so low that encoding and developing processes are interrupted. Because the image data are intermittently transmitted from the remote facsimile to be stored in the image data memory, the amount of the image data put into the image data memory becomes greater than the amount taken out for decoding and developing processes. As a result, the amount of image data stored in the image data memory increases until finally the image data memory becomes full.
The image data memory also becomes full when decoding or developing processes of image data are complicated. In this case, the data amount stored in the image data memory increases while the complicated decoding or developing processes are being performed. Especially when the record data memory is almost fully filled with the record data, the remaining capacity in the memory unoccupied by the record data is so low that the decoding or developing process are frequently interrupted. As a result, the image data memory is more liable to become full.
When the facsimile machine is not provided with an error correction mode (ECM) function, the full image data memory will cause a transmission error because flow control of transmission of the image data can not be performed. Therefore, the full image data memory will cause reception of incoming image data to be cut off.